It's possible the calliper is sticking. To check, jack up front of car and see if each front wheel spins freely. Also, what type of pads are you using?
In my experience with brakes (I've always done my own), the metalic pads are very tough on rotors.
What type rotors are you using?
I always try to stay with oem stuff even though it costs a bit more.
It really sounds like your calliper is sticking though.
Good luck.